lec 25: biodiversity & conservation ecology

biodiversity

biological diversity

genetic diversity

total genetic information

• measured as # and relative frequency of all genes & alleles

• higher genetic diversity = greater change variation is beneficial to environmental change

diversity measures of species

1. species diversity

   1. richness (total #)

   2. evenness (similar relative abundances)

   3. count species (DNA barcodes)

2. phylogenetic diversity

   1. how diversity spread across tree of lie

3. functional diversity

   1. ecological/functional roles represented

species richness

• affects biomass: NPP higher in more diverse ecosystems

• has positive impacts on NPP

  • resource use efficiency: diverse plants more efficient → more biomass

  • facilitation: certain species assist growth of other species by providing benefits

  • chance inclusion of high-productivity species: if 1 or 2 species extremely productive, NPP depends on whether species are in study plot

    • high-species plot outproduce low-species plots

horizontal diversity

number of species in each trophic level

vertical diversity

number of trophic levels

ecosystem diversity

measure of complex factors & interactions with abiotic environment

ecosystem function

sum of biological & chemical processes that are characteristic of given ecosystem

• includes primary production, nitrogen cycling, decomposition, & carbon cycling

• is a product of organisms in a system interacting with abiotic environment

stability of a community

ability to

• maintain productivity & ecosystem functions as conditions change

• recover to form levels or productivity or species richness after disturbance

resistance

measure of how community is affected by disturbance

• increased by diversity

resilience

measure of how quickly a community recovers following a disturbance

• increased by diversity

human perspective: ecosystem services

provisioning services: raw materials

• food, fuel, fiber, medicines

regulating services: part of earth’s life support system

• climate moderation, soil formation, erosion control

cultural services: enrich quality of life

• aesthetics, recreation, education

supporting services: enable other ecosystem services

• primary productivity, nutrient cycling, pollination, pest control

biodiversity threats

• habitat destruction & degradation

• overexploitation

• invasive species & disease

• pollution

• climate change

conservation strategies

• education campaigns

• ex situ conservation & reintroduction: endangered species in controlled environment

• genetic restoration

• wildlife corridors

• seed banks

• designating effective protected areas

• management plants for invasive species

• ecosystem restoration

• management plans for threatened species

• quantifying ecosystem services